The invention relates generally to peristaltic pumps, and more particularly to a peristaltic pump having means to facilitate loading and unloading of tubing.
Peristaltic pumps are preferred for certain applications due to their ability to pump fluids through tubing without any contact between pump components and the fluid being pumped. In certain contexts, such as laboratory uses, it may be desirable to change tubing frequently in a particular pump. Various efforts have been made to enable removal and insertion of tubing with relatively little time and effort.
The provision of a mechanism for quickly and easily opening the pump to permit loading and unloading of tubing, and closing the pump to permit peristaltic pumping, involves several considerations. Among these is the fact that in the closed position, the occlusion bed must be stably supported in a desired spatial relationship to the rotor, notwithstanding relatively high dynamic pumping forces directed radially outward against the occlusion bed during pumping. The locking mechanism must be capable of withstanding such forces and operational loads without loosening. Any increase in the distance between the occlusion bed and the rotor changes occlusion and consequently results in variation of flow rates. Other considerations that must be taken into account are the need for the pump to be capable of economical manufacture, and durable so as to withstand normal operating loads without undue wear.
U.S. Pat. No. 4,813,855 discloses a mechanism which provides a practical and effective means to facilitate changing of tubing. The mechanism employs a cam arrangement whereby the pump is opened or closed by a single stroke of a manually-operable handle through an arc of about 180.degree..
The present invention relates to an improved mechanism which employs the advantages of the mechanism described in U.S. Pat. No. 4,813,855 and provides additional advantages as set forth below.